AT RISK: The BPA found in baby bottles could harm infants.

The draft report by the National Toxicology Programme, an office of the National Institutes of Health, released on Tuesday said that experiments on rats found pre-cancerous tumours, urinary tract problems and early puberty when the animals were fed or injected with low doses of BPA.

It called for more research into the chemical's health effects. 'What we have got is a warning, a signal of some concerns,' said Mr Mike Shelby, director of the Centre for Evaluation for Risks to Human Reproduction. 'We could not dismiss the possibility that similar or related effects might occur in humans.'

Public health advocates said the report should spur the government to ban BPA, at least in baby products.

An ingredient of polycarbonate plastic, BPA is one of the most widely used synthetic chemicals in industry today.

Formula-fed infants are most vulnerable to the chemical because it is found in baby bottles as well as the linings of canned powdered and liquid formula.

'They get a double exposure,' said Dr Anila Jacob, a senior scientist at the non-profit Environmental Working Group.

But Mr Steven Hentges, executive director of the polycarbonate/BPA global group at the American Chemistry Council, said the new report does not mean BPA is unsafe.

'It found no serious or high-level concerns for human health,' he said. 'More research is always considered valuable.'

The toxicology panel used a five-level rating system, ranging from serious concern to negligible concern. It labelled the possible cancer risk of BPA as 'some concern', in the middle of the scale.

There was not enough scientific evidence to rank it as a 'concern' or 'serious concern', Mr Shelby said.

The draft report followed an 18-month review that was fraught with allegations of bias, heated disputes among scientists and the firing of a consulting company with financial ties to industry.

WASHINGTON POST, ASSOCIATED PRESS